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J Ruan

Publications and source records attributed to J Ruan.

30 records · Page 2Linked to original sources
PubMed1997

A proposal to revive the genus Kitasatospora (Omura, Takahashi, Iwai, and Tanaka 1982).

We determined almost complete 16S ribosomal DNA sequences for 12 actinomycete strains which were either previously classified as Kitasatospora strains or defined as Streptomyces strains but shown to contain major amounts of meso-diaminopimelic acid in their whole-cell hydrolysates. These sequences were subjected to phylogenetic analyses together with the sequences of 34 Streptomyces species. Phylogenetic trees were reconstructed by using both neighbor-joining and maximum-parsimony methods. The Kitasatospora species always formed a stable monophyletic clade. However, the genus Kitasatospora appeared to be either a sister taxon of the genus Streptomyces or a lineage that originated from within Streptomyces species, depending on the outgroup used. Phylogenetic trees were also constructed by using the sequences of the 16S-23S rRNA gene spacers. Streptomyces and Kitasatospora species were consistently recovered as two distinct clades independent of the outgroup used. On the basis of phylogenetic, chemotaxonomic, and phenotypic evidence, we propose that the genus Kitasatospora Omura et al. 1982 should be revived.

Actinomycetaceae↗
PubMed1997

Evaluation of bacterial survival and phagocyte function with a fluorescence-based microplate assay.

To compare antibacterial function in macrophages from mice deficient in the respiratory burst oxidase or inducible nitric oxide synthase, we developed a fluorescence-based microplate assay of bacterial survival. As bacteria grow, they convert a formulation of resazurin termed AlamarBlue from its nonfluorescent oxidized state to its fluorescent reduced state. The time required to achieve a given fluorescence is inversely proportional to the number of viable bacteria present when the dye is added. This relationship allows a precise, accurate assessment of bacterial numbers with greater sensitivity and throughput and at less cost than conventional assays. The assay facilitated quantification of the killing of Escherichia coli by S-nitrosoglutathione and hydrogen peroxide and of Salmonella typhimurium by human neutrophils and mouse macrophages. Mouse macrophages lacking the 91-kDa subunit of the respiratory burst oxidase were deficient in their ability to kill S. typhimurium, while those lacking inducible nitric oxide synthase were unimpaired.

Animals↗
PubMed1997

Effect of low-frequency ultrasound on peritoneal transport in rabbits.

It has recently been suggested that sonophoresis, or the application of ultrasound (US) in the kilohertz range, could enhance peritoneal mass transport. To examine this hypothesis, six nephrectomized rabbits were exposed to ultrasound while under isoflurane anesthesia. An additional five also had bilateral nephrectomies and were used as a control group. Each group underwent four exchanges of 90 minutes duration with 1.5% dextrose while anesthetized. Dialysate samples were taken at 0, 30, 60, and 90 minutes and assayed for urea, creatinine, glucose, and protein. Blood samples were taken pre- and postexchange. In the US group, 20 kHz ultrasound was applied during exchanges 2 and 3 at 47.5 W and 95 W, respectively, using a Virsonic 475 cell disrupter acoustically coupled to the abdomen through a water column and gel-coated PVC membrane. Results were analyzed by calculating the mass transfer area coefficient (MTAC) and 90-minute D/P values for each exchange. No significant differences were observed in the absolute means of either parameter between the control and US groups. However, when exchanges 2 to 4 were normalized with respect to exchange 1, the resulting urea D/P means were less for the US exchanges compared to the control (p < 0.05). This suggests a possible decrease in transport through US application.

Animals↗
PubMed1996

Inducible nitric oxide synthase requires both the canonical calmodulin-binding domain and additional sequences in order to bind calmodulin and produce nitric oxide in the absence of free Ca2+.

All three mammalian isoforms of nitric oxide synthase (NOS) must bind calmodulin (CaM) for enzymatic activity. Only NOS2 (the inducible isoform, iNOS) does so at the low levels of free Ca2+ in resting cells and when almost all Ca2+ is chelated in cell-free preparations. To test directly whether the predicted CaM-binding region of mouse NOS2 accounts for its Ca2+ independence, we prepared chimeric NOS's in which mouse NOS2 residues 503-532 were reciprocally exchanged with the corresponding residues 725-754 of rat NOS1 (neuronal NOS). Unlike either parent, both chimeras required an intermediate level of free Ca2+ to bind CaM and generate NO. In cell lysates, the concentration of Ca2+ necessary for half-maximal activity (EC50) was approximately 0 for NOS2, 200-300 n for NOS1, and 7-10 n for the chimeras. Results were similar when the region exchanged was enlarged by 7-8 residues toward the amino terminus. In contrast, when the carboxyl-terminal half of NOS2 (residues 454-1144) was replaced with that of NOS1 (residues 675-1429), the resulting chimera resembled NOS1 (EC50, 200-300 n free Ca2+). Truncation analysis suggested that NOS2 residues within the sequence 484-726 were required for Ca2+-independent CaM-binding. Thus, both the canonical CaM-binding domain and additional residues within the region 484-726 are necessary for NOS2's ability to bind CaM and produce NO when Ca2+ levels approach zero.

Amino Acid Sequence↗
PubMed1996

Phylogenetic analysis reveals new relationships among members of the genera Microtetraspora and Microbispora.

The 16S rRNA gene sequences of 7 Microbispora strains, 14 Microtetraspora species, 9 Streptosporangium species, and 12 Actinomadura species were determined. A phylogenetic analysis showed that Microtetraspora fusca, Microtetraspora glauca, and Microtetraspora niveoalba formed a coherent cluster with the members of the genus Microbispora. This cluster is distantly related to two other clusters, one of which consists of the Microtetraspora species transferred from the former Actinomadura pusilla group and one of which consists of members of the genus Streptosporangium. Our results show that it is necessary to review the taxonomic definitions of the genera Microtetraspora and Microbispora, which have been separated by a single morphological characteristic, the number of spores on spore chains.

Actinomycetales↗
PubMed1996

A proposal to transfer Microbispora bispora (Lechevalier 1965) to a new genus, Thermobispora gen. nov., as Thermobispora bispora comb. nov.

We determined almost complete 16S rRNA gene sequences of two Microbispora bispora (Lechevalier 1965) strains, ATCC 19993T (T = type strain) and JCM 3082. The two sequences were 99% similar to each other but exhibited only 81 to 87.8% similarity with the 16S rRNA gene sequences of seven other Microbispora strains. A phylogenetic analysis revealed that the two sequences clustered not only distantly from other Microbispora strains, but also outside the cluster containing members of the family Streptosporangiaceae. On the basis of the results of our phylogenetic analysis and the results of a comprehensive review of the genus Microbispora by Miyadoh et al. (S. Miyadoh, S. Amano, H. Tohyama, and T. Shomura, J. Gen. Microbiol. 136:1905-1913, 1990) in which chemotaxonomic and DNA-DNA hybridization analyses were performed, we propose that Microbispora bispora should be transferred to a new genus, Thermobispora gen. nov., as Thermobispora bispora comb. nov.

Actinomycetales↗
PubMed1995

[Dynamic observation of alpha-granule membrane protein 140 during the treatment of thrombolytic and anticoagulant therapy in patients with acute myocardial infarction].

The degree of platelet activation and damage in 15 cases with acute myocardial infarction (AMI) receiving thrombolytic therapy and 15 cases with AMI receiving anticoagulant therapy were studied in vivo and in vitro by using specific monoclonal antibodies (SZ-51 & S12) against alpha-granule membrane protein 140 (GMP-140). Clinical indexes and myocardial enzyme changes in the two groups of patients were also observed. The results showed that the number of GMP-140 molecules on platelet surface and the concentration of GMP-140 in plasma were increased before treatment. The number of GMP-140 molecules on platelet surface began to decrease on the 1st day and returned to baseline on the 7th day after treatment. The concentration of GMP-140 in plasma reached a peak on the 1st day, began to fall on the 2nd day and returned to baseline on the 3rd day after treatment. There were no significant differences in the dynamic changes of number of GMP-140 molecules on platelet surface and the concentration of GMP-140 in plasma between groups of thrombolytic therapy and anticoagulant therapy. In vitro experiment showed that the thrombolytic medicine urokinase neither activated platelets nor inhibited platelet activation induced by thrombin. Significantly greater reperfusion rate and earlier appearance of CK and CK-MB peaks were found in the thrombolytic than in the anticoagulant group. LVEF determined by echocardiography, rate of return of ST segments to baseline and alleviation rate of chest pain were significantly greater and complications of AMI (ventricular fibrillation, left ventricular failure and angina) were less in the group receiving thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Study of interaction between vitamin D2 and excipients by use of diffuse reflectance spectra].

The interaction of Vit D2 with calcium compounds and excipients commonly used was studied by use of diffuse reflectance spectra (DRS). The results indicated that there was some interaction between Vit D2 and calcium lactate, glucose, and a strong interaction between Vit D2 and magnesium stearate; and that the interaction between Vit D2 calcium gluconate, CaHPO4, sucrose, starch, lactose and mannitol was very weak and could even be neglected.

Drug Interactions↗
PubMed1994

[Lupus nephritis treated with impact therapy of cyclophosphamide and traditional Chinese medicine].

UNLABELLED: 41 active lupus nephritis patients were treated vigorously with cyclophosphamide (CTX), steroid used as routine, as well as TCM administered according to the various disease stage. 35 cases administered with same western medicine but no TCM was taken as control group. RESULT: After a six-month treatment course, the therapeutical efficacy was significantly higher in treated group than that in control group (P < 0.05). Lupus nephritis usually manifested itself as Liver-Kidney Yin deficiency in TCM. Our study suggested that Chinese herbs might play an important role in the treatment of lupus nephritis.

Adolescent↗
PubMed1991

[Identification of twenty-eight species mycobacteria with their cellular fatty acids by capillary gas chromatography].

Cellular fatty acid (FA) of 28 species of mycobacteria were analysed by capillary gas chromatography (GC). There were more than sixty volatile FA before C12:0 have no any difference between species both in quality and quantity. The identification scheme of Mycobacterium based on cellular FA was presented here. According to this scheme, all the tested species could be divided into 8 groups by the FA peak height order of C18:1, C18:0 and TBSA which were quite stable; after that, 17 species (60%) might be identified to species level with help of some distinctive FA such as C19:0, C21:0. Most pathogenic bacteria could be separated by the scheme (M. tuberculosis, M. bovis and some complexes). This scheme was also demonstrated to be objective rationality by computer cluster analysis with cellular FA components.

Chromatography, Gas↗